Tripod leg clamp



Aug. 13, 1940.

J. s. BE'GGS 2,211,314

TRIPOD LEG CLAMP Filed May 22, 1957 Z1 zo Joseph SZileS Beggs 1N VENTOR.

j BY ./W A

AT RNEYS Patented Aug. 13, 1940 UNITED STTES TRIPOD LEG CLAMP Joseph Stiles Beggs, Rochester, Y., assigner to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application May 22, 1937, Serial No. 144,230

10 Claims.

f which comprise slidably united sections; and particularly to the means for rigidly clamping these slidably united sections in any desired position.

Ordinary tripods, such as are at present commonly used in cameras of Various kinds, surveying instruments, etc., are constructed with light adjustable and collapsible legs. To provide light, strong, and rigid devices the legs are each formed of two upwardly diverging sides, and in order that they may be adjustable and collapsible the legs are constructed in sections adapted to adjustably telescope. The clamping means generally provided with this type of leg structure for holding the telescoping leg sections in adjusted position are inconvenient to operate so that a considerable amount of time is required for prop- I erly setting up the tripod. In addition, most tripods having adjustable leg sections as above described are designed primarily for supporting objects which are comparatively light, and as a result the clamping means for the legs are not designed to give a clamping action which will support the heavier cameras as used by professionals.

Therefore, one object of the present invention is the provision of a clamping means for the telescoping legs of a tripod which is easy to manipulate without inconvenience to the operator. Another object is the provision of a clamping means the operating handle of which can be used to adjust the telesooping leg sections into the desired position so that only one hand is required to adjust and clamp any one leg section. A further object is the provision of a clamp by means of which the adjustable leg can be frictionally secured in any desired position rigidly enough to support a comparatively heavy weight. And still another object is the provision of a clamping means which is so designed that only a comparatively slight adjustment of the operating handle is required to alter the clamping means from a locking to an unlocking position. Another object is to provide a clamping means the engaging parts of which are enclosed so that they are protected against the elements and the accumulation of dirt. And yet another object is to provide a clamping means which is neat in appearance, designed for long life, and constructed so that the parts thereof cannot become disengaged and lost.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments whenread in connection with the accompanying drawing in which,

Fig. l is a side elevation of a tripod, and showing the preferred embodiment of my invention 10 applied thereto,

Fig. 2 is an enlarged sectional View taken substantially on line 2 2 of Fig. l, and showing one embodiment of the clamping structure.

Fig. 3 is a horizontal section taken through one of the clamps, and showing the preferred embodiment of my structure in unlocking position,

Fig. 4 is a similar to Fig. 3 but shows the clamp in locking position, and

Fig. 5 is a section taken on line 5-5 of Fig. 1.

Like reference characters refer to corresponding parts throughout the drawing.

Referring now to the drawing, numeral I0 designates a tripod head which is supported by legs Il, Each tripod leg ii comprises angular leg sections i2 to the upper ends of which are bolted brackets i3. These brackets I 3 engage extensions i4 on the tripod head and are pivotally connected thereto by a clamping bolt I5 by means of which the legs H can be held in any desired angular position relative to the tripod head. Angular leg sections It are connected at their lower ends by a coupling I l and diverge upwardly in telescoping relation with respect to the angular leg sections l2, as shown clearly in Figs. 2-5. Bands i8 are iixed to the lower leg sections I2 by screws I 9 to extend around and form a guide for the leg sections i6 which telescope with the leg sections i2, see Fig. 5. Supporting feet indicated at 9 can be removably attached to the coupling i'i in any suitable manner, said feet having pointed or rubber ends as may be desired.

The upper ends of the leg sections It are fastened to rectangular casings 20 which serve both as a housing in which the clamping mechanism is enclosed and as a guide member for holding the two angular leg sections I2 and it in telescoping relation, as will be hereinafter described. Each casing 2t constitutes a substantially closed housing, the top 2i and bottom 2l of which are provided with angular openings 22 through which the leg sections l2 and i6 extend to be held in telescopic relation. The upper ends of the angular sections i6 extend completely through the bottom of the casing and through the top of the casing far enough to be ilushwith the outer surface of the top 2| thereof, see Figs. 1 and 2. The angular leg section I6 is situated in one corner of the casing 20 so that its arms are fastened to the wall of the casing in any suitable manner such as by rivets 43 as shown in Figs. 2 4. The angular section I2 extends completely through the angular opening 22 in the top and bottom of the casing 2|] to be guided in telescopic relation with the angular section I6 thereby, see Figs. 2 4.

As shown in Figs 3 and 4, a triangular pressure block 23 is situated in each casing 2S so that one of its vertices lies in the vertex of the angular leg section I2, and the surfaces of the legs thereof engage the faces of the arms of the angular section. A wedge 24 is movably mounted in each casing 28 to move crossways thereof, and is provided with an angular face 25 which is adapted to engage the hypotenuse of the triangular pressure block when moved theretoward.

The wedge 24 is provided with a bore 25 the one end of which is threaded to be engaged by a threaded end on the nut member 21 The nut member 21 extends through and is rotatably mounted with respect to an aperture in the wall 28 of the casing 20, and is provided with a flange 29 which engages the wall of the casing to prevent its passage through the aperture therein. It will be readily understood that when the nut member 21 is rotated in one direction, the wedge 24 will be drawn toward the wall 28 in the casing whereupon the face 25 thereof will engage the hypotenuse of the triangular pressure block 23 and will press said block toward the vertex of the angular section I2 and force this leg section into frictional engagement with the angular section IB to thereby clamp the leg in its adjusted position, see Fig. 4. A rotation of the nut member in the opposite direction will move the wedge 24 away from the triagular pressure block 23 and will allow the angular section I2 to move away from the angular section I6 so that the leg Section IS can slide relative thereto. It will be appreciated that only a very slight movement of the wedge 24 is required between its locking and unlocking positions, and referring to Figs 3 and 4, it will be understood that the casing 20 is designed so as to permit sufficient movement of the wedge 24 for moving between its locking and unlocking positions, but not allowing sufficient movement thereof so that the nut member 21 and the wedge 24 can become disengaged.

Although the nut member 21 can be rotated in any manner to provide an adjustment of the wedge 24, in order that a simultaneous adjustment of the wedges 24 in their respective cases 2B of each leg I I can be effected, I have provided the following structure.' Each nut member 21 is provided with a hexagonal bore 3U into which the ends of a hexagonal adjusting rod 3| extends so that the rod is slidable axially to the nut member but cannot be rotated relative thereto. It is to be understood that the bore 30 in the nut member 21 and the adjusting rod 3| cooperating therewith can be of any complementary shape such as triangular, rectangular, or the like, so long as a splined fitting is provided. A handle 32 is situated on the adjusting rod intermediate the upper ends of the angular leg section I6, and has a hexagonal bore engaging the hexagonal rod so that it can slide relative toy the rod but cannot rotate with respect thereto, see Figs. 1 and 2. Coil springs 33 encircle the rod 3| on either side of a handle 32, and have one end engaging the nut member 21 and the other end seated in a recess 34 in the end of the handle 32 which is coaxial with the hexagonal bore therein. These springs 33 tend to position the handle 32 on the rod 3| so that it will be equally spaced from each of the diverging leg sections I6 regardless of whether the leg is collapsed or fully extended.

So that the rotation of the adjusting rod 3| will eifect a simultaneous clamping or unclamping action in each of the clamping mechanisms of any one leg II, the threads on the nut members 21 are formed oppositely. In other words, the screw thread on one of the nut members 21 is left handed while the screw thread on the other nut member is right handed. It was discovered that when the adjusting rod 3| is rotated, the right and left hand nut members did not pick up their respective wedge members simultaneously, but one lagged slightly behind the other with the result that an uneven clamping occurred in the two clamps. To overcome this fact, equalizing spring washers 35 are positioned between the ange 29 on each of the nut members 21 and the wall 28 of the casing 20, see Figs. 3 and 4, and said spring washers serve to equalize the pressure on the two clamps by allowing the nut member 21 to move relative to the wedge 24.

The above described clamping means operates in the following manner: When the tripod leg II is to be adjusted the handle 32 is rotated in the proper direction to cause the wedges 24 to move into the unclamping position shown in Fig. 3. Without removing the hand from the handle 32, the angular leg sections IG and the clamping means xed thereto and enclosed in the casing 20, are pulled up or shoved downward as the case may be by pulling or shoving on the handle 32, and when the desired position is obtained the handle is rotated in the opposite direction to effect a clamping of the leg section. It will be appreciated that since this leg structure provides a clamping means whereby the operating handle can be used to extend the legs as well as clamp them in any adjusted position, one hand will suffice to adjust and clamp the leg while the other may be used to steady the instrument mounted on the tripod head.

From the above description it will be understood that as the angular leg sections I6 are extended from their collapsed position, shown in Fig. l, the casings 2U will be moved toward one another due to the divergence of the leg sections. As the casings 20 move toward or away from one another during the adjustment of the legs II, the adjusting rod 3| slides relative to the hexagonal bore in the nut members 21 and passes through the bore 26 in the wedge 24 and into the casing 2D. The arrangement of the parts is such that when the legs II are collapsed and the angular leg sections I6 are spaced apart the maximum distance, the ends of the adjusting rod 3| will not pull out of the bore in the nut member 21; and when the legs are completely extended and the casings 20 are a minimum distance apart, the casing 29 will be deep enough to allow the ends of the rod 3| to pass thereinto.

Referring now to Fig. 2 wherein a second embodiment of my invention is shown, the entire structure is the same with the exception that the triangular pressure block 23 is replaced by a cylindrical roller 36 which lies in the vertex of the angular leg section I2. The roller 36 is situated in the casing 2U so that the elements of the periphery contact the surface of the arm of the angular leg section I2.

The wedge 24' 75 is modied slightly in shape as compared to the Wedge 24 of Figs. 3 and 4 so that its face 25 will engage an element on the periphery of the roller 36 whereby a movement of the wedge toward the wall 28 of the casing 2li will force the roller toward the vertex of the angular leg section I2 to force said leg section l2 into frictional clamping engagement with the angular section I6. It

is obvious that the roller 3@ which engages the arm of the angular leg section I2 in line contact is not as effective in forcing said leg section into frictional engagement with the angular leg section I6 as is the triangular pressure block Z3 which engages the arms of the leg section l2 through surface contact, but this embodiment is shown and described in order to illustrate one of the many Ways in which my novel structure canv be modified Without lgoing beyond the scope of the invention. v

It willvbe readily understood that a clamping means for telescoping leg sections as above set forth is easy to manipulate and provides a very rigid joint with a slight movement of the adjusting means. By transmitting pressure from the screw driven wedge 24 to the angular leg sections I2 through the medium of a triangular pressure block 23, which has a comparatively large area in surface contact with the arm of said angular leg section, a comparatively large area of frictional contact is provided between the telescopiing leg sections whereby a rigid clamping is secured. The particular arrangement of parts allows the clamping means to be released or locked through a slight adjustment of the adjusting handle so that a rapid adjustment can be made Without necessitating the release of said adjusting handle.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modiiications thereof are possible. My invention, therefore, is not to be restricted except in so far as is necessitated by the prior art and by the spirit of the appended claims.

Having thus described my invention, what I declare is new and desire to secure by Letters Patent of the United States is:

1. In a tripod having an adjustable leg formed of adjustable telescopiing sections, means for frictionally clamping the sections together, said means comprising a casing surrounding said sections and fixed to one thereof, a pressure member in said casing and adapted to engage one of said sections, a wedge movably mounted in said casing and for applying pressure to said pressure member in a direction to force the telescopiing section into frictional engagement with one another, and an adjusting means connected with said wedge for moving it into and out of engagement with the pressure member.

2. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping the sections together, said means comprising a casing surrounding said sections and xed to one thereof, a pressure member in said casing and adapted to lie in the vertex of one of said angular sections, a wedge movably mounted in the casing and adapted to engage and force said pressure member toward the vertices of the angular sections to clamp the sections, and an adjusting means connected to the Wedge for moving the samerelative to the pressure member.

3. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping the sections together, said means comprising a casing surrounding said sections and xed to one thereof, a cylindrical roller l within said casing and situated in the angle o1' one of the angular sections so that its periphery contacts the two surfaces constituting said angular section, a wedge movably mounted in said casing to engage and force the roller toward the vertex of the angular section to clamp the leg sections, and an adjusting means connected to said wedge for moving the same relative to the roller. v

4. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping the sections together, said means comprising a casing surrounding said sections and fixed to one thereof, a triangular pressure block within said casing and situated in the vertex of one of the angular sections, a wedge movably mounted in said casing to engage the hypotenuse of the triangular pressure block and force it toward the vertices of the angular sections to clamp the same, and an adjusting means connected to said Wedge for moving the same relative to the pressure block.

5. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping the sections together, said means comprising a casing surrounding said sections and iixed to one thereof, a triangular pressure block within said casing and situated in the vertex of one of the angular sections, a wedge movably mounted in said casing to engage the hypotenuse of the triangular pressure block and force it toward the vertices of the angular sections to clamp the same, a nut extending through said casing into threaded engagement with said wedge, and means for rotating said nut to move the Wedge into engagement with the pressure block to clamp said angular sections.

6. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping the sections together, said means comprising a casing surrounding said sections and fixed to one thereof, a triangular pressure block within said casing and situated in the vertex of one of the angular sections, a

Wedge movably mounted in said casing to engage th hypotenuse of the triangular pressure block and force it toward. the vertices of the angular sections to clamp the same, a nut extending into and rotatably mounted with respect to said casing, said nut being in threaded engagement with the wedge and having a polygonal bore, and a polygonal rod slidable in said bore and for rotating said nut tomove said Wedge into engagement with the pressure block whereby the angular sections are frictionally clamped.

7. In combination, a pair of telescoping angular sections, a casing surrounding said sections and fixed to one thereof, a second pair of telescoping, angular sections spaced from the first mentioned pair, a casing surrounding the second pair of sections and fixed to one thereof, a triangular pressure block within each casing and situated in the vertex of one of the angular sections, a Wedge movably mounted in each of said casings to engage the hypotenuse of the triangular pressure block therein and force it toward the Vertex of the angular sections to clamp the same, an adjusting means for each wedge member for moving the same into and out of engagement with its respective pair of angular sections, and a single operating member connecting both of said adjusting means whereby the separate wedge members can be simultaneously moved into or out of clamping position in their respective casings through the actuation thereof.

8. In combination, a pair of telescoping angular sections, a casing surrounding said sections and fixed to one thereof, a second pair of telescoping angular sections spaced from the rst mentioned pair, a casing surrounding the second pair or" sections and xed to one thereof, a triangular pressure block Within each casing and situated in the vertex of one of the angular sections, a Wedge movably mounted in each casing to engage the hypotenuse of the triangular pressure block therein and force it toward the vertices of the angular sections to clamp the saine, a nut member extending through and rotatably mounted with respect to each of said casings, each of said nut members being in threaded engagement with the Wedge in its associated casing and having a polygonal bore therethrough, and a polygonal rod having its ends extending into the bores in the nut members Whereby a rotation of said rod will cause the nut members to rotate and move the wedge members into or out of their clamping positions simultaneously depending upon the direction of rotation of said rod.

9. In combination, a pair of telescoping angular sections, a casing surrounding said sections and fixed to one thereof, a second pair of telescoping angular sections spaced from the first mentioned pair, a casing surrounding the second pair of sections and xed to one thereof, a triangular pressure block Within each casing and situated in the vertex of one of the angular sections, a Wedge movably mounted in each casing, to engage the hypotenuse of the triangular pressure block therein and force it toward the vertices of the angular sections to clamp the same, a nut member extending through and rotatably mounted with respect to each of said casings, each of said nut members being in threaded engagement spaced intermediate the pairs of angular sections regardless of the relative position of the ends of the polygonal rod and the nut members.

10. In combination, a pair of telescoping angular sections, a casing surrounding said sections and fixed to one thereof, a second pair of telescoping angular sections spaced from the first mentioned pair, a casing surrounding the second pair of sections and fixed to one thereof, a triangular pressure block Within each casing and situated in the vertex of one of the angular sections, a wedge movably mounted in each casing to engage the hypotenuse of the triangular pressure block therein and force it toward the vertices of the angular sections to clamp the same, a

nut member extending through and rotatably y' mounted with respect to each of said casings each of said nut members being in threaded engagement with the wedge in its associated casing and having a polygonal bore therethrough, a polygonal rod passing through the bores of the nut members to be slidable but not rotatable with respect thereto, a handle slidably mounted on but fixed against rotation with respect to said polygonal rod between the pairs of angular sections for rotating the same, and means associated with each of the nut members and arranged to effect the relative axial movement between the nut member and its respective wedge, and for equalizing the pressure on the two clamps.

JOSEPH STILES BEGGS. 

